Rapid generation method of trigger pulse of cascaded H-bridge multilevel converter

Abstract

The invention relates to a generation method of the switching trigger pulse of a cascaded H-bridge multilevel converter, belonging to the switch modulation technical field of the power electronic converter. The invention mainly aims at the conflict between the generation precision of trigger pulse, and the number of sampling points and the computing workload, in the existing converter switch sine pulse width modulation (SPWM) trigger pulse generation technology and provides the generation method of the switching trigger pulse of the cascaded H-bridge multilevel converter, wherein the generation method is based on the carrier phase shifted-SPWM (CPS-SPWM) technology. According to the specific sampling method, sampling time sequence and algorithm of duty cycle of the invention, the SPWM trigger pulse of the converter switch can be generated rapidly. Compared with the existing CPS-SPWM pulse generation technology based on the symmetrical rule sampling method, the SPWM trigger pulse generated by the method of the invention has high precision; and compared with the CPS-SPWM pulse generation technology based on the unsymmetric rule sampling method, the number of the sampling points and the computing workload are reduced to half. In addition, by adopting the method, the time delay between the fundamental component of the output voltage of the converter and the modulated wave is small, namely the generation speed of the trigger pulse is high.

Description

technical field [0001] The invention relates to a method for forming a trigger pulse of a converter switch, in particular to a method for quickly generating a trigger pulse for cascaded H-bridge type multilevel converter switching devices. Background technique [0002] Among the many switching modulation strategies applied to cascaded H-bridge multilevel converters, the carrier phase-shifted sine pulse width modulation (CPS-SPWM) technology has a high equivalent switching frequency , the output voltage harmonic content is small, the signal transmission bandwidth is wide, and the control method is simple, and it is widely used. Performance such as sex has an important impact, and determines the sampling frequency and the complexity of the algorithm when the CPS-SPWM technology is realized. The technology described in the present invention is mainly aimed at cascaded H-bridge type multilevel converter switching devices, based on the CPS-SPWM pulse modulation technology, accor...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the contradiction between the trigger pulse generation accuracy and the number of sampling points and the calculation workload in the existing converter switch SPWM trigger pulse forming technology, and to provide a CPS-SPWM for cascaded H-bridge multi-level converters The trigger pulse generation method, according to the specific sampling method, sampling timing and duty cycle algorithm of the present invention, quickly forms the trigger pulse of the converter switching device

Images